垂直轴风力发电机的设计

对垂直轴风力发电机进行了基本的参数计算,运用了产品造型设计中的仿生形态学理论,设计出的风力机叶片外形跟蝴蝶翅膀的轮廓相似,叶片的数量为三个,三叶片互成120°并且有折叠单元,不仅实用而且具有一定的观赏性.对风力发电机做了简单的人机工程学分析,主要包括风力机尺寸、颜色、材料的选取,色彩要结合考虑该风机使用地点环境的整体颜色,光线饱和度以及仿生形态原型的主要颜色,材料选用强度高、比重轻、抗蚀性好以及耐久的高质量复合材料.最后对风力机载荷进行分析跟讨论,使得垂直轴风力发电机造型美观,性能实用.     

Simple vibration model for the design of a vertical axis wind turbine

Journal of Mechanical Science and Technology - Wind turbines are widely used these days as one of renewable energy sources. In this paper, a dynamic model of a vertical axis wind turbine is...     

垂直轴阻力型风力机平均功率计算及分析

垂直轴阻力型风力机可用于风力发电及风速测量,在实际应用中较精确计算风力机功率对进行风能利用评价和风力机站构设计都是至关重要的.本研究通过风力机叶片受力情况分析,给出了风力计算公式和平均功率计算公式,运用Matlab工具具体计算了一小型风力机实例,初步分析了功率与风速、叶片阻力系数等关系,得出了相应的阻力型风力机叶尖速比.分析表明垂直轴阻力型风力机的风能利用率不高,但结构简单、适应性较强.     

垂直轴风力发电机结构研究进展

与水平轴风力发电机相比,垂直轴风力发电机具有结构对称、风能利用率高、噪音低等优点,有着较为广阔的市场前景。首先对垂直轴与水平轴风力机作了比较,分析了垂直轴风力发电机的特点,简要地概述了垂直轴风力机的先后发展,分别介绍了常见的萨渥纽斯阻力型、达里厄型及其变形结构等垂直轴风力机的结构,阐述了国内外学者对垂直轴风力机结构的研究现状,最后简要地分析了设计垂直轴风力机所面临的主要问题。     

Aerodynamic design and performance analysis of multi-MW class wind turbine blade

The rotor blade is an important device that converts kinetic energy of wind into mechanical energy. It affects power performance, efficiency of energy conversion, load and dynamic stability of a wind power generation system. This paper presents an aerodynamic design of 3 MW class blade using BEM and confirms that the design satisfies the initial design target by BEM and CFD analysis. To investigate the effects of radial flow at the inboard region, the result of static BEM analysis was compared with the result of CFD analysis. The result of quantitative comparison among thrust force, power coefficient and mechanical power depending on wind speed change is presented. Furthermore, design reference data such as pressure, streamline, torque and thrust force distribution on the blade surface is presented as well.     

垂直轴风力机流场模拟计算网格划分研究

垂直轴风力机是一种全风向工作、结构简单可靠的风力发电能量转换机械,用CFD软件对其流场进行分析、研究,最为关键的是对数值模型进行网格划分。针对垂直轴风力机流场的特点,结合实践运用情况,给出了其网格划分的基本方法及注意要点。     

垂直轴风力机应用概况及其展望

水平轴风力机是当今应用最广的一种风力机,垂直轴风力机也有着自身优越的性能,并越来越被人们所重视。介绍垂直轴风力发电机与水平轴风力发电机的优缺点,以及垂直轴风力机的最新应用及其发展趋势。     

垂直轴阻力型风力机功率计算方法研究

垂直轴阻力型风力机是一种全风向工作、结构简单可靠的风力发电能量转换机械,在实际应用中较精确计算风力机功率对风能利用评价和风力机结构设计都是至关重要的.通过不同的方法分别对两种垂直轴阻力型风力机的平均功率计算进行了研究,给出了风力机功率计算具体的研究方法和平均功率计算公式,比较分析了不同功率计算方法的适用情况,得出了功率...     

Estimation of power in low velocity vertical axis wind turbine

The present work involves in the construction of a vertical axis wind turbine and the determination of power. Various different types of turbine blades are considered and the optimum blade is selected. Mechanical components of the entire setup are built to obtain maximum rotation per minute. The mechanical energy is converted into the electrical energy by coupling coaxially between the shaft and the generator. This setup produces sufficient power for consumption of household purposes which is economic and easily available.     

复合新翼型风力机叶片的气动设计及建模

基于Wilson法,用美国可再生能源实验室开发的S系列新翼型S833、S834、S835和三者的组合翼型来设计叶片,不同翼型连接处采用MATLAB程序语言的样条差值和曲线拟合法进行过渡修正,以满足气动连续性要求。在叶片设计基础上,分别计算了单翼型和复合翼型叶片的气动性能;利用有限元分析软件ANSYS建立了风轮的三维实体模型。结果表明:复合翼型叶片在较宽尖速比范围内比其它几种单翼型叶片的功率系数大,利用ANSYS软件建立的风轮实体三维模型,为风轮的结构动态及载荷等问题的进一步分析提供了技术基础。     

Numerical and experimental investigation of wind loadings on vertical axis wind turbine blade deflection

This work focuses on experimental and numerical investigation of the deflection on VAWT blade surface against the high measured wind speeds that were simulated in FLUENT to obtain the corresponding static forces. The effect of forces, blade setting angle and thickness to chord ratio along with their combined effects on deflection were assessed experimentally and numerically. Three airfoils of gradually increasing thickness to chord ratio, NACA 0015, 0021 and 4412, were selected along with three levels of forces and tested at 5°, 10° and 15° of blade setting angle. A 3³ factorial experimental design was used to perform experiments and Analysis of variance (ANOVA) confirmed that individual effects of force and thickness to chord ratio were the most significant factors while blade setting angle had lesser significance on deflected values. However, interactive effects of these parameters were significant. Minimum deflections were observed in the range of 0.25-0.28 mm on NACA 0021 at 3 kg force in combination with all blade setting angles. Maximum observed value of defection was 1 mm, which occurred at 9 kg force at 5°, 10° and 15° of blade setting angle on NACA 0015 and 4412 airfoil shapes. The results ensure that the blade structure remains stable at 9 kg which corresponds to 20 m/s wind speed without affecting the performance. The deflections obtained from Finite element method were compared with experimental results and found in good agreement with each other.

     

Investigation on aerodynamics and active flow control of a vertical axis wind turbine with flapped airfoil

A 2D unsteady numerical simulation with dynamic and sliding meshing techniques was conducted to solve the flow around a threeblade Vertical axis wind turbine (VAWT). The circular wakes, strip-like wakes and the shedding vortex structures interact with each other result in an extremely unstable performance. An airfoil with a trailing edge flap, based on the NACA0012 airfoil, has been designed for VAWT to improve flow field around the turbine. Strategy of flap control is applied to regulate the flap angle. The results show that the flapped airfoil has an positive effect on damping trailing edge wake separation, deferring dynamic stall and reducing the oscillating amplitude. The circular wake vortices change into strip vortices during the pitch-up interval of the airfoils. Examination of the flow details around the rotating airfoil indicates that flap control improves the dynamic stall by diminishing the trend of flow separation. Airfoil stall separation has been suppressed since the range of nominal angle of attack is narrowed down by an oscillating flap. Vortices with large intensity over rotational region are reduced by 90 %. The lift coefficient hysteresis loop of flapped airfoil acts as an O type, which represents a more stable unsteady performance. With flap control, the peak of power coefficient has increased by 10 % relative to the full blade VAWT. Obviously, the proposed flapped airfoil design combined with the active flow control significantly has shown the potential to eliminate dynamic stall and improve the aerodynamic performance and operation stability of VAWT.     

某燃气涡轮气动设计及通用特性曲线计算

针对燃气轮机中涡轮的设计,介绍了杭汽燃气涡轮气动设计体系,并阐述了冷却涡轮掺混损失计算方法和几种效率定义方法。通过一维热力设计和S2流面完全径向平衡方程设计,设计出了三级燃气涡轮。应用计算流体力学软件CFX对所设计的涡轮进行了不带冷气的性能分析,应用源项法对带冷气的涡轮进行了性能分析。通过三维计算,得到了新设计的三级涡轮的折合流量、折合转速、效率的特性曲线;并为涡轮的进一步气动优化设计和强度振动校核打下了基础。计算结果显示:设计的涡轮气动性能良好,变工况性能宽,基本达到了设计要求;不带冷却涡轮效率91%,带冷却的涡轮效率89.7%。     

PIV measurements over a double bladed Darrieus-type vertical axis wind turbine: A validation benchmark

Vertical axis wind turbines (VAWTs) are very attractive for in-home power generation since they can be adopted even at low wind speeds and highly variable wind direction. Even if significant experimental research activity has been carried out to improve VAWTs performance, the ability to accurately reproduce flow field characteristics around turbine blades by CFD (computational fluid dynamics) techniques represents a powerful approach to further enhance wind turbines performance. Thanks to CFD, in fact, it is possible to reproduce flow characteristics with a detail level impossible to achieve by experiments. Nevertheless, in order to appropriately analyze the flow structure by CFD application, an accurate validation is essential, and high-quality measurements of some main flow characteristics are required. In recent publications the authors investigated, both experimentally and numerically, the performance of an innovative double bladed Darrieus-type VAWT, with the aim to define an optimal configuration also focusing on self-starting ability of the prototype by employing CFD technique. Nevertheless, comparison between experiments and numerical results was made only in terms of power and torque coefficients. To overcome such limitation, in this paper the authors propose an experimental benchmark case for CFD results validation, describing detailed flow field in correspondence of one pair of blades of the innovative Darrieus-type VAWT in static conditions. Measurements were performed employing Particle Image Velocimetry (PIV) technique on a scaled model of the turbine blades realized by 3D printing. An uncertainty analysis was also performed which showed a high accuracy of the obtained experimental results. The measurements of the main flow characteristics (bi-dimensional velocity components) were then used for a test case CFD validation of two different turbulence models.     

垂直轴风力机二维非定常流场数值模拟

应用FLUENT软件求解二维非定常不可压N-S方程和SST κ-ω湍流模型,采用PISO速度压力修正算法,结合滑动网格技术,模拟垂直轴风力机(VAWT)的流场特性.获得并分析了不同时刻的速度场、压力场分布,风轮叶片受力和转矩的变化规律.结果表明绕流场模拟能有效地反应风力机旋转过程的流场状况,可为垂直轴风力机的工程设计提供理论依据.     

风机塔架的模态分析及优化设计

对塔架进行了结构设计,利用Ansys软件对塔架进行模态分析,从而对塔架的应力、最大位移变形量进行仿真分析.通过一个实例,对改进前后塔架的固有频率和振型进行对比分析,验证塔架有限元建模的正确性,为塔架的优化设计提供理论依据.并将所设计的塔架应用于实际生产中,取得了良好的经济效益.     

水平轴风力机叶片气动性能计算及影响因素分析

叶片作为风电机组的关键部件之一,其设计和可靠性直接关系到风力发电机组的安全运行,而气动性能的好坏将会直接影响到叶片外形设计及机组效率。因此,对叶片进行气动性能计算和数值模拟成为必要。根据动量叶素理论建立风力机叶片气动计算模型,考虑到叶尖损失,叶根损失,叶片宽度和厚度等因素的影响对该模型进行修正。用MATLAB语言编制计算程序,针对某一具体翼型数据进行了气动性能的计算,分析了风轮实度、安装角、锥角以及偏航等因素对叶片气动性能的影响。     

风力发电机的造型设计

通过对风力发电机的形态设计学研究、空气动力学方面的研究以及机舱内的人机工程学研究从而设计出不仅造型美观而且能提高整体运行的效率、使用寿命的风力发电机。     

1+1/2对转涡轮的气动设计与分析

主要进行的是1 1/2轴流式对转涡轮的气动设计研究。发展了1 1/2对转涡轮的设计体系,采用基于流线曲律法的可控涡方法对1 1/2对转涡轮进行S2流面的设计,对叶型设计方面的工作进行了探索,在传统的参数法叶型设计程序的基础上发展运用bezier曲线进行叶型优化,并采用商用CFD软件开展对转涡轮S1流场和全三维粘性流场的数值计算。     

低速高效垂直轴风力发电机及其特性分析

针对低风速区风力发电机需要低风速切入问题,研究了一种低速高效的定子无铁芯轴向磁通永磁风力发电机。对影响发电机性能的关键参数对进行了归纳,提出了一种单层非重叠集中绕组和优选"切饼"型磁极组合的设计理念。确定了定子无铁芯轴向磁通永磁风力发电机性能分析参数方案。利用三维有限元发电机设计平台,对发电机的空载输出特性,交、直流负载输出特性和不同转速下的负载输出特性进行了对比研究。研究结果表明,该结构发电机的各项基本电磁参数和输出特性均能满足低速风力发电系统的特殊要求:优选的磁极结构使发电机总永磁体耗用量节约11.5%,发电机最大输出效率达87.75%;低转速范围运行时,效率维持在85%以上;不同工况下输出电能总谐波畸变率低于3%。